exam6 Flashcards
What stain would you use for genus Mycobacterium?
acid-fast stain
What genus will stain as an acid fast bacilli?
Mycobacterium
How does Genus Mycobacterium look?
thin, straight rods, tend to clump
How is Genus Mycobacterium classified?
growth rates
colonial colors
If you were to run a gram stain on Genus Mycobacterium, how would it stain?
gram positive
What type of media is required to grow mycobacterium in a lab?
selective media such as Lowenstein agar, Middlebrook agar
Describe the cell wall of genus mycobacterium.
complex waxes
long chained fatty acids “mycolic acids”
What is the mycobacterium quality that makes the cell wall difficult to stain and difficult to decolorize when you get it stained?
the presence of long chained fatty acids “mycolic acids” and waxes in the cell wall
Why does genus mycobacterium need a selective media?
mycobacterium has a slow growth rate of the pathogenic species
What is the causative agent of tuberculosis?
Mycobacterium tuberculosis
What is the primary lesion of someone who is infected with mycobacterium tuberculosis?
tubercle
How is mycobacterium tuberculosis spread?
pulmonary, through aerosols (droplets)
When someone is infected with mycobacterium tuberculosis, what is causing most of the damage? What is being inhibited?
damage: macrophages
inhibited: lysosomal fusion (the phagosome and lysosome will NOT come together)
Is mycobacterium tuberculosis phagocytized?
YES
BUT the fusion of the phagosome and lysosome is INHIBITED
What are the virulence factors of mycobacterium tuberculosis?
cording factor
cell wall lipids
What bacteria is associated with the Ghon complex?
mycobacterium tuberculosis
Describe a Ghon complex.
macrophages surround the organism, leading to central caseous necrosis/ lesions
Why do calcified lesions develop in someone suffered from untreated mycobacterium tuberculosis?
The body doesn’t like holes in tissues. This is the body trying to fill in where there has been macrophage damage because they have been trying to do their job.
If you are needing to differentiate an image you see on an X-ray from TB or a fungal infection, what test should you order?
acid fast stain
A positive result of a TB skin test is what hypersensitivity reaction?
Type 4 (delayed)
What does PPD stand for?
purified protein derivative
If you have a positive skin test for TB, does that mean you HAVE TB?
It means you have been exposed
Which TB skin test is done by sticking the antigen into the skin?
HINT: like stabbing someone with FORK
Tine test
Which TB test is done by injected a little but of antigen under the skin?
Mantoux Test
If you see a lump of induration after the initial poke from your TB test, what does that indicate?
positive skin test
What would be the next step if someone comes back with a positive TB skin test?
get chest x-ray
What does XRTB stand for?
extremely resistant TB
How would a case of mycobacterium tuberculosis be treated?
long term (6-9 months) combination of antibiotics
What organism is used as a vaccine against mycobacterium tuberculosis?
mycobacterium bovis
What is the BCG vaccine problematic?
gives permanent positive skin test
What does BCG vaccine stand for?
Bacille Calmette Guerin
What organism may cause respiratory disease in cows?
mycobacterium bovis
How is mycobacterium bovis spread to humans?
through unpasturized milk
When would you need to be concerned about mycobacterium bovis?
with cows outside of the USA and those unpasteurized milk products
What organism has the reservoir of armadillos?
Mycobacterium leprae
What is the reservoir of Mycobacterium leprae?
armadillos
What is the causative agent for Hansen’s disease?
Mycobacterium leprae
What disease does Mycobacterium leprae cause?
Hansen’s disease (leprosy)
What environment does mycobacterium leprae prefer?
cooler areas of body
extremities, this is also why armadillos are the reservoir
What is damage seen with mycobacterium leprae?
damage is IMMUNE RELATED damage to extremities nerve damage bone reabsorption secondary infections
What are the forms of mycobacterium leprae?
lepromatous
tuberculoid
How is mycobacterium leprea treated?
sulfa drugs